There are many circumstances in which surgeons prefer to operate laparoscopically instead of making relatively long incisions which characterize conventional surgery. Typically, a laparoscopic surgical procedure requires a surgeon to form small punctures into a patient's abdominal region, to position via the punctures a plurality of cannulae, and to dispose selected instruments via selected cannulae. Thus, for example, a surgeon may utilize one cannula both for conveying light into the patient's abdominal cavity via optic fibers and for viewing the lighted region via other light-receiving optic fibers and a television monitor. Another cannula may be used to introduce an insufflation gas and/or suction to remove bodily fluids or incidental detritus. Yet other cannulae may be utilized to introduce elongate surgical tools having respective end elements to perform particular functions.
The surgeon must exercise care and dexterity in lighting the zone of interest, carefully holding selected portions of the patient's internal tissues, and performing surgical operations such as incision, cauterization, sawing of bone/tendon, heat-fusion of tissue in lieu of conventional sewing, and the like. Even if the patient is under general anesthesia, the surgeon does not have unlimited time and must operate precisely, carefully, and as quickly as possible. Given the wide variety of surgical techniques and functions, it is therefore highly desirable and cost-effective to have modular tools which permit a variety of operations without requiring a correspondingly large number of separate surgical tools.
There is thus a distinct need for an adaptable surgical instrument in which tissue-contacting/manipulating end elements (often referred to as "end effector elements") may be selected from a modular supply of the same, with the selected elements being quickly and securely fitted operationally to a single hand-held surgical tool body. Furthermore, such an instrument should permit rapid detachment of used modular elements and other operational parts so that they may be quickly exchanged and/or sterilized for subsequent re-use. Various surgical instruments are known for performing at least some of these functions, as exemplified in the patents described below.
U.S. Pat. No. 5,263,967 to Lyons III, et al., titled "Medical Instrument With Dual Action Drive", discloses a medical instrument comprising end effector elements, e.g., jaw members, which are attached by a pivot relative to each other, each effector element being pin-fitted to an irregularly enlarged end of an inner rod slidably contained within a tubular element. The end of the inner element comprises a pair of arms which deliver force required to rotate the cooperating end effectors toward one another. A variety of end effector elements such as grippers, hole-punchers, dissectors, extractors, scissors and clamps, may be employed.
U.S. Pat. No. 5,290,309 to Kothe, titled "Surgical Instrument", discloses an instrument particularly suitable for endoscopy, having closable cooperating jaw parts such as forceps or scissor limbs which are fixed on a pull element. At least one of the jaw parts forms an axis of rotation with the pull element and has a recess in its outer portion. The center point of the recess rotates about a pivot on the pull element. Each recess at least partially surrounds an annular end portion formed in the inside wall of an elongate outer tube, so that each jaw part rotates about this annular portion during closing or opening movement.
U.S. Pat. No. 5,275,615, to Rose, titled "Medical Instrument Having Gripping Jaws", teaches a device having a hand-held portion comprising pivotable handles carried on an instrument body from which projects an elongated tube surrounding a push-pull elongate inner rod. The rod carries a pivotal jaw arrangement and projects outwardly from a distal end of the tube for tissue grasping or gripping. A spherical piston or rack and pinion gear connects the distal end of the rod with the jaw arrangement and a rod travel limit stop is operably connected between the handle, the rod and the instrument body.
U.S. Pat. No. 5,147,357, to Rose, et al, titled "Medical Instrument", discloses a generally similar instrument additionally provided with an electrode carried on the body for supplying energy to the rod and jaw arrangement for cauterization.
Despite the availability of such devices, there still exists a need for a simple hand-operable surgical instrument suitable for laparoscopic surgical procedures which can be readily adapted for a variety of purposes by quick and secure change of end effector elements, with quick replacement of effector elements also to facilitate sterilization of used elements. The present invention is intended to meet this need, and will be best understood by persons of ordinary skill in the art from the following description with appropriate reference to the attached figures.